[Mono-devel-list] [PATCH] CAS declarative stack modifiers - affects JIT ports!

[Paolo Molaro]

On 12/08/04 Sebastien Pouliot wrote:
> This is a newer version of the previous patch that use callbacks when
> playing with the stack. I.e. the current code for getting debug info
> from the stack has been re-written to use the callback, while the new
> security code use it.

What I had in mind for the stack walking callback is attached.
The code is untested, but it should work well enough for your
needs and doesn't have the large overhead of creating managed
objects etc, which is not needed at all.
We should also add a macro to the mini-$arch.h files to init
the starting context:

#define MONO_INIT_CONTEXT_FROM_FUNC(ctxstart_func) do {\
		mono_arch_flush_register_windows ();	\
		MONO_CONTEXT_SET_IP ((ctx), (start_func));	\
	 	MONO_CONTEXT_SET_BP ((ctx), __builtin_frame_address (0));	\
	} while (0)

So we can finally reuse this code on other archs, too, remove the useless
flush_register_windows() on !sparc etc.
Would this work for you?

lupus

-- 
-----------------------------------------------------------------
lupus at debian.org                                     debian/rules
lupus at ximian.com                             Monkeys do it better
-------------- next part --------------
Index: mini.h
===================================================================
--- mini.h	(revision 37690)
+++ mini.h	(working copy)
@@ -816,6 +816,11 @@
 gboolean mono_handle_exception                  (MonoContext *ctx, gpointer obj,
 						 gpointer original_ip, gboolean test_only);
 void      mono_jit_walk_stack                   (MonoStackWalk func, gboolean do_il_offset, gpointer user_data);
+
+/* the new function to do stack walks */
+typedef gboolean (*MonoStackFrameWalk)          (MonoDomain *domain, MonoContext *ctx, MonoJitInfo *ji, gpointer data);
+void      mono_walk_stack                       (MonoDomain *domain, MonoJitTlsData *jit_tls, MonoContext *start_ctx, MonoStackFrameWalk func, gpointer user_data);
+
 MonoArray *ves_icall_get_trace                  (MonoException *exc, gint32 skip, MonoBoolean need_file_info);
 MonoBoolean ves_icall_get_frame_info            (gint32 skip, MonoBoolean need_file_info, 
 						 MonoReflectionMethod **method, 
Index: mini-exceptions.c
===================================================================
--- mini-exceptions.c	(revision 37690)
+++ mini-exceptions.c	(working copy)
@@ -154,7 +154,49 @@
 	return res;
 }
 
+/**
+ * mono_walk_stack:
+ * @domain: starting appdomain
+ * @jit_tls: JIT data for the thread
+ * @start_ctx: starting state of the stack frame
+ * @func: callback to call for each stack frame
+ * @user_data: data passed to the callback
+ *
+ * This function walks the stack of a thread, starting from the state
+ * represented by jit_tls and start_ctx. For each frame the callback
+ * function is called with the relevant info. The walk ends when no more
+ * managed stack frames are found or when the callback returns a TRUE value.
+ * Note that the function can be used to walk the stack of a thread 
+ * different from the current.
+ */
 void
+mono_walk_stack (MonoDomain *domain, MonoJitTlsData *jit_tls, MonoContext *start_ctx, MonoStackFrameWalk func, gpointer user_data)
+{
+	MonoLMF *lmf = jit_tls->lmf;
+	MonoJitInfo *ji, rji;
+	gint native_offset;
+	gboolean managed;
+	MonoContext ctx, new_ctx;
+
+	ctx = *start_ctx;
+
+	while (MONO_CONTEXT_GET_BP (&ctx) < jit_tls->end_of_stack) {
+		/* 
+		 * FIXME: mono_find_jit_info () will need to be able to return a different
+		 * MonoDomain when apddomain transitions are found on the stack.
+		 */
+		ji = mono_find_jit_info (domain, jit_tls, &rji, NULL, &ctx, &new_ctx, NULL, &lmf, &native_offset, &managed);
+		if (!ji || ji == (gpointer)-1)
+			return;
+
+		if (func (domain, &new_ctx, ji, user_data))
+			return;
+		
+		ctx = new_ctx;
+	}
+}
+
+void
 mono_jit_walk_stack (MonoStackWalk func, gboolean do_il_offset, gpointer user_data) {
 	MonoDomain *domain = mono_domain_get ();
 	MonoJitTlsData *jit_tls = TlsGetValue (mono_jit_tls_id);